Peanut butter scented glue traps. Sounds crazy, but we used to have to replace them 2-3 times a month for one customer because they were so covered with scorpions that there wasn't any room for more. We would also find quite a few stingers broken off on them, which means a scorpion got loose, but was rendered at least temporarily harmless. (Don't recall which ones can re-grow a stinger, or how long it takes.)